Shi Hong-Xing, Qu Jiu-Hui, Wang Ai-Min, Ge Jian-Tuan
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Chemosphere. 2005 Jul;60(3):326-33. doi: 10.1016/j.chemosphere.2004.11.070. Epub 2005 Jan 13.
A new and efficient method for the degradation of microcystins (one family of blue algal toxins) was developed and studied. Microcystins (MCs) in water were directly and effectively removed by active chlorine transformed in situ from the naturally existing Cl- in water resource using electrochemical method. Titanium coated with RuO2 and TiO2 was used as the anode. Microcystin-RR (MCRR) and Microcystin-LR (MCLR) were chosen as the model compounds of MCs. The results suggested that 20.87 mgl(-1) MCs (12.58 mgl(-1) MCRR and 8.29 mgl(-1) MCLR) in aqueous solution with 1.85 mM Cl- could be synchronously decomposed within 15 min electrolysis under the condition of the current density 8.89 mAcm(-2), 20 degrees C and pH 7.00. The qualitative analysis showed that the heptapetide ring and the Adda group of both treated MCs were changed. The results also indicated that the removal rates of both MCs increased with the increasing of chloride concentration and applied current density, but decreased with the increasing of initial concentration of MCs and initial pH of electrolyte. In the absence of Cl-, only a small fraction of both MCs were decomposed by direct anodic oxidation, while their almost complete removals could be obtained in the case of indirect electrooxidation with in situ electrogenerated active chlorine from Cl- in water.
开发并研究了一种降解微囊藻毒素（一类蓝藻毒素）的新型高效方法。利用电化学方法将水资源中天然存在的Cl-原位转化为活性氯，可直接有效地去除水中的微囊藻毒素（MCs）。以涂覆有RuO2和TiO2的钛作为阳极。选择微囊藻毒素-RR（MCRR）和微囊藻毒素-LR（MCLR）作为MCs的模型化合物。结果表明，在电流密度8.89 mAcm(-2)、20℃和pH 7.00的条件下，对含有1.85 mM Cl-的水溶液进行15分钟的电解，可使其中20.87 mgl(-1)的MCs（12.58 mgl(-1) MCRR和8.29 mgl(-1) MCLR）同步分解。定性分析表明，两种被处理的MCs的七肽环和Adda基团均发生了变化。结果还表明，两种MCs的去除率均随氯化物浓度和施加电流密度的增加而提高，但随MCs初始浓度和电解质初始pH值的增加而降低。在没有Cl-的情况下，两种MCs只有一小部分通过直接阳极氧化分解，而在用水中的Cl-原位电生成活性氯进行间接电氧化的情况下，它们几乎可以被完全去除。
